The radiation sterilization of male mosquitoes is being studied by an entomologist as a potential biological weapon to combat the mosquito-borne Zika virus outbreak in the Americas.
“After decades of fighting mosquitoes – and mostly losing – technology is bringing new biological weapons to the battle,” reports the New Zealand online news outlet Stuff.
Maureen Coetzee, an entomologist at South Africa’s University of Witwatersrand and international expert on mosquito control, is “conducting research on an anti-malaria strategy that involves breeding male mosquitoes, sterilizing them with radiation and releasing them into the wild,” notes the report.
This approach could also be applied to control Aedes aegypti, the mosquitoes that spread Zika.
“The concept was pioneered in the 1950s when US scientists used it to eradicate the screwworm fly,” points out Stuff, referring to radiation-sterilization. “Applied to mosquitoes, it relies on two basic facts: They mate only once, and only females bite.”
“The strategy depends on releasing enough mosquitoes to crowd wild males out of the mating game, letting the current generation die out without reproducing,” it adds.
Mosquitoes reportedly live for two to four weeks.
Coetzee is quoted as arguing that effective control of mosquitoes “would require releasing millions monthly during malaria season across vast areas.”
The radiation-induced sterility technique reportedly allows targeting of individual species of mosquitoes, which is described as one advantage of the strategy over other methods.
“It makes sense to target only those mosquitoes that are involved in transmission of disease,” explained the researcher.
Although Coetzee and other scientists have no qualms about trying to kill off the certain species, Stuff notes, the researcher acknowledged that goal is “highly unlikely.”
“There’s no silver bullet,” she added.
Stuff concedes that the sterile insect approach is best used in combination with other methods, such as insecticides.
However, the use of insecticides to control mosquito populations has its limits, adds the report.
“Mosquito populations have grown increasingly resistant, a global problem that Coetzee places on par with the rise of bacteria resistant to antibiotics,” according to Stuff.
Another reported shortcoming of insecticides is that mosquito breeding sites are easily overlooked, indicated Laith Yakob, a vector control expert at the London School of Hygiene and Tropical Medicine.
The use of genetically modified male mosquitoes was described as the newest variation of using radiation to produce sterile males.
“It involves genetically modifying male mosquitoes so their offspring are programmed to die before they mature and are able to reproduce,” notes Stuff.
“Some scientists believe genetic modification is better than sterilization, because dousing mosquitoes with radiation could leave them less vibrant and hurt their ability to compete with their wild counterparts when it comes to mating,” it adds.
The Zika virus has been linked to microcephaly, a neurological disorder that causes babies to be born with abnormally small heads and developmental problems. It has also been associated with Guillain-Barré, a rare syndrome that causes the immune system to damage nerve cells, leading to muscle weakness and even paralysis.